export function buffer (fn, ms) {
  let timer

  function clear () {
    if (timer) {
      clearTimeout(timer)
      timer = null
    }
  }

  function bufferFn () {
    clear()
    timer = setTimeout(fn, ms)
  }

  bufferFn.clear = clear

  return bufferFn
}

export function isSamePoint (prev, next) {
  if (prev === next) return true
  if (!prev || !next) return false

  if ('pageX' in next && 'pageY' in next) {
    return prev.pageX === next.pageX && prev.pageY === next.pageY
  }

  if ('clientX' in next && 'clientY' in next) {
    return prev.clientX === next.clientX && prev.clientY === next.clientY
  }

  return false
}

export function isWindow (obj) {
  return obj && typeof obj === 'object' && obj.window === obj
}
